/Engine/Plugins/Developer/Concert/ConcertMain/Source/ConcertClient/Public/IConcertClient.h
Usually, a client would create a new empty repository and set it as default to populate it, then keep the ID to reload/drop it later.
[TFuture](API\Runtime\Core\Async\TFuture)< [FConcertAdmin_MountSessionRepositoryResponse](API\Plugins\Concert\FConcertAdmin_MountSessionReposi-_1) > MountSessionRepository ( const [FGuid](API\Runtime\Core\Misc\FGuid) & ServerAdminEndpointId, const [FString](API\Runtime\Core\Containers\FString) & RepositoryRootDir, const [FGuid](API\Runtime\Core\Misc\FGuid) & RepositoryId, bool bCreateIfNotExist, bool bAsDefault ) const